Mark Rutland
0ed557aa81
sched/core / kcov: avoid kcov_area during task switch ...
During a context switch, we first switch_mm() to the next task's mm,
then switch_to() that new task. This means that vmalloc'd regions which
had previously been faulted in can transiently disappear in the context
of the prev task.
Functions instrumented by KCOV may try to access a vmalloc'd kcov_area
during this window, and as the fault handling code is instrumented, this
results in a recursive fault.
We must avoid accessing any kcov_area during this window. We can do so
with a new flag in kcov_mode, set prior to switching the mm, and cleared
once the new task is live. Since task_struct::kcov_mode isn't always a
specific enum kcov_mode value, this is made an unsigned int.
The manipulation is hidden behind kcov_{prepare,finish}_switch() helpers,
which are empty for !CONFIG_KCOV kernels.
The code uses macros because I can't use static inline functions without a
circular include dependency between <linux/sched.h> and <linux/kcov.h>,
since the definition of task_struct uses things defined in <linux/kcov.h>
Link: http://lkml.kernel.org/r/20180504135535.53744-4-mark.rutland@arm.com
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-15 07:55:24 +09:00
treewide: Use array_size() in vzalloc()
2018-06-12 16:19:22 -07:00
treewide: Use array_size() in vmalloc()
2018-06-12 16:19:22 -07:00
Kbuild: rename CC_STACKPROTECTOR[_STRONG] config variables
2018-06-14 12:21:18 +09:00
treewide: kzalloc() -> kcalloc()
2018-06-12 16:19:22 -07:00
treewide: kzalloc_node() -> kcalloc_node()
2018-06-12 16:19:22 -07:00
gcov: remove CONFIG_GCOV_FORMAT_AUTODETECT
2018-06-08 18:56:02 +09:00
Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2018-06-10 09:44:53 -07:00
livepatch: Allow to call a custom callback when freeing shadow variables
2018-04-17 13:42:48 +02:00
treewide: kzalloc() -> kcalloc()
2018-06-12 16:19:22 -07:00
treewide: Use array_size() in vmalloc()
2018-06-12 16:19:22 -07:00
Printk changes for 4.18
2018-06-06 16:04:55 -07:00
treewide: Use array_size() in vmalloc()
2018-06-12 16:19:22 -07:00
sched/core / kcov: avoid kcov_area during task switch
2018-06-15 07:55:24 +09:00
Power management updates for 4.18-rc1
2018-06-05 09:38:39 -07:00
treewide: Use array_size() in vmalloc()
2018-06-12 16:19:22 -07:00
kernel/async.c: revert "async: simplify lowest_in_progress()"
2018-02-06 18:32:44 -08:00
audit: use inline function to get audit context
2018-05-14 17:24:18 -04:00
audit: track the owner of the command mutex ourselves
2018-02-23 11:22:22 -05:00
audit: track the owner of the command mutex ourselves
2018-02-23 11:22:22 -05:00
audit: use inline function to get audit context
2018-05-14 17:24:18 -04:00
audit: use existing session info function
2018-05-18 15:47:54 -04:00
audit: Fix wrong task in comparison of session ID
2018-05-21 14:27:43 -04:00
Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2018-06-04 20:27:54 -07:00
cpu/hotplug: Fix unused function warning
2018-03-15 20:34:40 +01:00
mm: split page_type out from _mapcount
2018-06-07 17:34:37 -07:00
delayacct: Use raw_spinlocks
2018-04-27 14:34:51 +02:00
proc: introduce proc_create_single{,_data}
2018-05-16 07:23:35 +02:00
proc: introduce proc_create_single{,_data}
2018-05-16 07:23:35 +02:00
kernel: use kernel_wait4() instead of sys_wait4()
2018-04-02 20:14:51 +02:00
extable: Make init_kernel_text() global
2018-02-21 16:54:06 +01:00
treewide: kmalloc() -> kmalloc_array()
2018-06-12 16:19:22 -07:00
mm: check for SIGKILL inside dup_mmap() loop
2018-06-15 07:55:24 +09:00
pids: introduce find_get_task_by_vpid() helper
2018-02-06 18:32:46 -08:00
kernel/hung_task.c: show all hung tasks before panic
2018-06-07 17:34:39 -07:00
memremap: split devm_memremap_pages() and memremap() infrastructure
2018-05-15 23:08:33 -07:00
jump_label: Disable jump labels in __exit code
2018-03-20 08:57:17 +01:00
sched/core / kcov: avoid kcov_area during task switch
2018-06-15 07:55:24 +09:00
kexec: call do_kexec_load() in compat syscall directly
2018-04-02 20:15:01 +02:00
kexec: yield to scheduler when loading kimage segments
2018-06-15 07:55:24 +09:00
treewide: Use array_size() in vzalloc()
2018-06-12 16:19:22 -07:00
kprobes: Fix random address output of blacklist file
2018-04-25 10:27:56 -04:00
kthread: Allow kthread_park() on a parked kthread
2018-05-25 08:03:51 +02:00
Merge branch 'core-rseq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2018-06-10 10:17:09 -07:00
mm: introduce MEMORY_DEVICE_FS_DAX and CONFIG_DEV_PAGEMAP_OPS
2018-05-22 06:59:39 -07:00
- Introduce arithmetic overflow test helper functions (Rasmus)
2018-06-06 17:27:14 -07:00
Kbuild: rename CC_STACKPROTECTOR[_STRONG] config variables
2018-06-14 12:21:18 +09:00
kernel/params.c: downgrade warning for unsafe parameters
2018-04-11 10:28:37 -07:00
xarray: add the xa_lock to the radix_tree_root
2018-04-11 10:28:39 -07:00
Merge branch 'userns-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
2018-04-03 19:15:32 -07:00
pids: introduce find_get_task_by_vpid() helper
2018-02-06 18:32:46 -08:00
kernel/relay.c: change return type to vm_fault_t
2018-06-15 07:55:24 +09:00
libnvdimm for 4.18
2018-06-08 17:21:52 -07:00
rseq: Introduce restartable sequences system call
2018-06-06 11:58:31 +02:00
audit/stable-4.18 PR 20180605
2018-06-06 16:34:00 -07:00
signal: Remove no longer required irqsave/restore
2018-06-10 06:14:01 +02:00
Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2018-06-04 19:59:22 -07:00
Linux 4.17-rc5
2018-05-15 08:10:50 +02:00
mm: introduce arg_lock to protect arg_start|end and env_start|end in mm_struct
2018-06-07 17:34:34 -07:00
Merge branch 'core-rseq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2018-06-10 10:17:09 -07:00
treewide: kzalloc() -> kcalloc()
2018-06-12 16:19:22 -07:00
staging: irda: remove remaining remants of irda code removal
2018-04-16 11:26:49 +02:00
pids: introduce find_get_task_by_vpid() helper
2018-02-06 18:32:46 -08:00
rcu: Rename cond_resched_rcu_qs() to cond_resched_tasks_rcu_qs()
2018-05-15 10:27:29 -07:00
tracepoints: Fix the descriptions of tracepoint_probe_register{_prio}
2018-05-28 12:49:51 -04:00
headers: untangle kmemleak.h from mm.h
2018-04-05 21:36:27 -07:00
fs: add do_fchownat(), ksys_fchown() helpers and ksys_{,l}chown() wrappers
2018-04-02 20:15:59 +02:00
kernel: provide ksys_*() wrappers for syscalls called by kernel/uid16.c
2018-04-02 20:15:30 +02:00
umh: fix race condition
2018-06-07 16:56:28 -04:00
efivarfs: Limit the rate for non-root to read files
2018-02-22 10:21:02 -08:00
treewide: kmalloc() -> kmalloc_array()
2018-06-12 16:19:22 -07:00
uts: create "struct uts_namespace" from kmem_cache
2018-04-11 10:28:35 -07:00
treewide: kzalloc() -> kcalloc()
2018-06-12 16:19:22 -07:00
workqueue: Set worker->desc to workqueue name by default
2018-05-18 08:47:13 -07:00
0ed557aa81